Flora of North America species comparison

straight, erect or nearly so (or leaning), cylindric, (20–)45–150(–300) × (20–)25–40(–50) cm;

ribs (18–)21–31, shallowly notched immediately above each areole.

12–32 per areole, central spines and larger radial spines whitish, yellow, pink, dull red, or brown;

smallest spines per areole slender, sometimes bristlelike, less than 1 mm diam. (rarely absent);

central spines 4 per areole, major rigid central spines surrounded by weaker subcentral spines;

principal central spine moderately curved, sometimes twisted, usually not strongly hooked except on relatively young plants, annulate, adaxial surface usually flat or even concave, 36–140[–170] × 2–4.5 mm.

maroon outside, yellow inside, 3–6 × 4–6 cm;

inner tepals commonly yellow, (rarely with reddish midstripes, very rarely orange to red with a darker red midstripes);

stigma lobes yellow (to red).

± readily dehiscent through basal pore, bright yellow (very rarely reddish), 30–40(–50) × 15–20 mm, leathery or fleshy, locule dry, hollow except for seeds.

(1.5–)2–3 mm, pitted.

= 22.